This disclosure relates to a gas turbine engine blade outer air seal assembly. More particularly, the disclosure relates to a seal for a blade outer air seal assembly.
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustor section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
A blade outer air seal assembly circumscribes an array of rotating blades in the turbine section. Typically, the blade outer air seal assembly is constructed from multiple arcuate blade outer air seal segments. Ends of adjacent segments are designed to seal relative to one another to prevent hot gases from the core flow path from penetrating the blade outer air seal assembly and undesirably increasing component temperatures.
Typically, the blade outer air seal assemblies are constructed from a high temperature, nickel-based superalloy, such as Mar-M-247. The ends are ship-lapped relative to one another to create a tortuous path that is more difficult for the hot gases to penetrate. The ends of the adjacent segments typically incorporate thin slots, where a thin, generally flat nickel-alloy seal is inserted to create a desirably sealed cavity to contain the cooling air, which is used to cool the segment, and prevent hot gases from the core flow path undesirably mixing with the cooling air. A thin, generally W-shaped nickel alloy seal is provided on a back face of the blade outer air seal segment joint to further obstruct the Z-shaped gap provided at the lap joint.